An electronic device for mobile communications (sometimes referred to as a terminal), such as a mobile telephone, may support wireless communications on plural radio frequency bands (also referred to as channels) for the same radio access technology. The electronic device also may support multiple radio access technologies, in which case the electronic device may support one or more frequency bands for each of the supported radio access technologies. Typically, not all supported bands are used simultaneously. Rather, the electronic device is configured to switch to a desired frequency band using one or both of software or hardware tuning technologies. The total number of bands supported in current electronic devices is typically about 10, but this number will vary depending on the specific electronic device, the manufacturer, the supported radio access technologies, etc. Exemplary cellular radio access technologies include, but are not limited to, GSM, CDMA, and WCDMA, and exemplary packet-switched network radio access technologies include, but are not limited to, WiFi and WiMAX.
There are some situations where an electronic device is power on and does not have stored data regarding a default network (also referred to as a home network) with which to attempt to communicate or cannot find a default network after attempting to communicate on channels associated with the default network. This may occur when the device is powered on for the first time and has not yet been affiliated with a subscriber network, when a subscriber identity module (SIM) card is changed (or added), or when travelling outside the coverage area of the home network. In this event, the electronic device starts a scan procedure in which each supported channel is scanned to identify a preferred network with which to communicate. This is often referred to as a full band scan. Full band scanning can take up to several minutes to complete scanning of each supported channel, although the scanning may be interrupted if a certain condition occurs such as identifying a preferred network or by finding another suitable radio access network. Typically, the scan involves scanning each supported channel in a serial manner (one after another) and in a default order.
Currently, the scan order for a full band scan is dictated by a specific register or part of the device's memory that stores the scan order. It is possible, in some cases, to reprogram that order but it is not convenient and requires a high level of knowledge to construct an order that would lead to scanning the lowest possible number of channels before reaching a satisfactory interruption point.